Scientific publications

The article relates the results of studies of the curly birch, Betula pendula Roth var. carelica (Mercklin) Hämet-Ahti, population in the Curly Birch Near the Village of Tsarevichi Botanical Reserve one of four specially established in the Republic of Karelia to protect and conserve this tree species. The basis for this reserve was the artificial curly birch population planted in 1934 and comprising at the time of designation some 450 trees. By now, the history of the nature reserve spans 90 years, and it must be acknowledged that the protected area status granted in 1984 has played and continues to play a decisive role in preserving curly birch there. In the spring of 2025, key growth parameters (height and trunk diameter) were measured in all trees within the population. Analysis of the data and comparison with records from 1976 and 2008, i.e. the past 50 years, shows that all the trees formed there have the high-stemmed growth form. The reason for that must be the high initial stocking density and the resulting intense competition among the trees (even after the accompanying species had been removed during tending). Furthermore, the light conditions which deteriorated as the trees grew affected not only their height but also their growth form, with many trees tending to slant towards open spaces. It was also found that illegal logging (mostly due to the vicinity of a village) and natural losses have resulted in a significant reduction (to 115 specimens) in the number of trees with visually detectable indirect signs of figured wood. However, even if many trees in this reserve exhibit weak or no signs of having figured wood, they still maintain a portion of the gene pool (and thus the genetic diversity) of the natural curly birch populations that had existed in Karelia a hundred or more years ago. Currently, the main adverse factors for the condition of trees in the reserve, aside from high stocking density, are the proximity of a heavily trafficked highway and the expansion of the nearby settlement in recent years.